The Federal Communications Commission (FCC) 911 mandates require a mechanism to provide the location of a 9-1-1 caller to the emergency services dispatcher. In landline telephone service, the location of the caller is determined based on the telephone number of the calling device. After the caller places an emergency call by dialing 9-1-1, a public safety answering point (PSAP) determines the location of the caller based on the physical address associated with the calling number. Since portable communication devices such as cellular handsets are not associated with a physical address, other techniques must be employed to determine the geographical location of the caller. These other techniques can be divided into two general categories, network based and handset based. Examples of network based techniques for determining a location of a cellular handset include Time of Arrival (TOA), Angle of Arrival (AOA), and Received Signal strength (RSS) techniques. Examples of handset based techniques for determining the geographical location of the handset include utilize Global Positioning Satellite (GPS), Assisted GPS (AGPS) and Advanced Forward Link Trilateration (AFLT).
Multimode portable communication devices are capable of operating within a cellular telecommunications system as well as wireless local area network (WLAN) systems. Multimode portable communication devices are capable of voice communications over cellular and WLAN systems. When operating in a WLAN system, voice over internet (VoIP) services are utilized for voice communications. WLAN systems typically employ smaller communication areas as compared to cellular systems. When communicating within the WLAN system however, the geographical location information of the portable communication device is either unavailable or unreliable. WLAN systems are typically deployed within buildings or in areas where cellular coverage and/or GPS coverage may be otherwise limited. Accordingly, when the portable communication device switches to a WLAN system, geographical location information may not be available for emergency personnel.
Therefore, there is a need for an apparatus, system, and method for managing geographical location information at a portable communication device.